Question about replacing control boards on Nomad

Like an idiot, I somehow caught the USB cable on something when I was moving the Nomad and it ripped the connector apart.

Like a Superhero, Jorge was on Skype with me to see what could be done. Alas, I needed a new board (which he shipped over)

I am hoping to not bug Jorge since I know they are busy building Nomads - so a quick question for the group. Can I just swap out the control board, no fuss no muss? Are there any special considerations since it’s electronic?


Well, keeping in mind that I’ve only opened up my Nomad and looked at the electronic board, as opposed to re-wiring it… (oh, well, I did replace my Z-axis motor once…)

There shouldn’t be any big problems with swapping the boards. However, there have been a few generational changes to the electronics that might cause some issues, so before touching anything, you want to do this:
0. Before opening the case, UNPLUG POWER AND USB. I once fried a $1000 board (inside a ~$100000 industrial robot), on a Saturday, by forgetting that the low-power communications cable connected to a board next to the one I was working on still carried some low voltage. Also, before touching the electronics board, make sure power and USB have been disconnected for at least an hour, just to ensure the capacitors have bled away their charges.

  1. Watch for static electricity. A grounding strap is best, but for modern electronics you’re probably safe just being careful and grounding yourself. Keep the new board in its anti-static bag as much as possible.
  2. Compare the old and new boards. Most especially, compare their connectors – make sure the same connectors are in the same place, have the same label and shape, and will accept the same cable connectors.
  3. Before disconnecting anything, put some labels on the cables. Each socket on the board has some fine print describing which motor/sensor it’s for. Take some photos, too. Heck, make a drawing, if you’re at all apprehensive – trace each cable from the board to what it plugs into, and write it down. Nothing firms up memory like having to re-write something yourself.
  4. Unplug all the cables from the board, and remove the board. Randy has actually done this, so hopefully he’ll chime in with some better details, but most of the connectors have (IIRC) little plastic tabs that “snag” a hook on the plug connector, and will need to be bent gently away before the plug will pull out. These tabs will also make it hard to plug a cable in upside-down, but it’s still worth making a note of which color wire goes on which end. I’ve never removed the board, but IIRC it’s just held in by a set of screws that should be easy enough to remove.
  5. Put the new board where the old board was. Put the screws back in.
  6. Plug each cable into the board, in the appropriate socket, referencing your drawing/photos/notes from Step 3.
  7. Before closing up the case, it’s probably a good idea to connect Power and USB and just try connecting to the Nomad and jogging it around a bit, maybe run a test cut program in air, just to make sure everything works. Obviously, keep kids, cats, and fingers out of the exposed electronics.
  8. Assuming everything works, just close up the electronics bay and the case again.
  9. PROFIT! or, you know, CNCing, or fun, or whatever.